Browsing by Author "Lulu Das"

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Anthracnose of orchids incited by glomerella Cingulata (Stonem) Spauld and Schrenk
(Kerala Agricultural University, 1994) Sreedharan, A; Lulu Das; Padmakumari, G
Biology and cultivation of Auricularia spp.
(Department of Plant Pathology, College of Agriculture, Vellayani, 2008) Vidyaresmi, C V; Lulu Das
The local strain of Auricularia polytricha collected from various parts of Thiruvanthapuram district as a part of study entitled “Biology and cultivation of Auricularia sp.” were used to study the modified cultivation techniques and overall acceptability of Auricularia mushrooms.This fungi preferred natural media such as potato dextrose agar and oatmeal agar , a temperature range of 30C and alkaline pH for their optimum growth.In vitro studies were conducted to find out the best carbon source and nitrogen source for its optimum growth. Sucrose was found to be the best carbon source and asparagines as the best nitrogen source. Time taken for maximum spawn run on different spawn substrates were tested and grain substrate was found to be a better spawn substrate than sawdust substrtae.Maize grain was found to be the best substrate for spawn run with a minimum of 16 days required for the fluffy growth of mycelium covering the substrate.Among sawdust substrates ,rubber sawdust was found to be the best substrate for spawn run with a minimum of 18 days required for the fluffy growth of mycelium covering the substrate.Yield of Auricularia sp. on different locally available cheap substrates were evaluated and rubber sawdust was found to be the best substrate giving maximum yield.Yield of Auricularia sp. on different food supplements along with available cheap substrates were evaluated and it was observed that addition of food supplements increased the yield of Auricularia sp.The proximate constituents of Auricularia mushroom were tested and it was observed that Auricularia sp. has high percentage of moisture,protein and carbohydrate content.The results of the organoleptic studies showed that Auricularia sp. has high cooking quality and good overall consumer acceptability.
Comparative efficiency of lignocellulolytic fungi for bioconversion of coirpith
(Department of Plant Pathology, College of Agriculture, Vellayani, 2002) Reeja, R S; Lulu Das
Nine lignocellulolytic fungi, of which SIX viz., Pleurotus eous, P. squarrosulus, two strains of Calocybe indica, Schizophyllum commune and Coprinus comatus collected from Thiruvananthapuram district as a part of the study entitled "Comparative efficiency of lignocellulolytic fungi for bioconversion of coirpith" and three from AfCRP Centre on Mushrooms, College of Agriculture, Vellayani were used to find out their ability to decompose coirpith. All these fungi preferred natural media such as Oatmeal Agar and Potato Dextrose Agar, a temperature range of 25 -. 35°C and neutral to acidic pH for their optimum growth. , ' I In vitro studies were conducted to find out the efficient strains. Pre and post composting physico-chemical analysis were carried out. Coirpith was found to be acidic in nature. EC of non retted coirpith was very high. Ability of these fungi in degrading organic carbon, cellulose and lignin thereby narrowing down the C : N ratio and increasing the nutrient status were found out. Field level trials using P. eous, P. squarrosulus, P. sajor-caju, P. florida, C. indica-Z and S. commune revealed that all these fungi could efficiently degrade coirpith, Better degradation of retted and non retted coirpith was observed when they were inoculated with lignocellulolytic fungi for 45 days. Maximum reduction in organic carbon and C : N ratio was brought about by P. eous and S. commune in non retted coirpith. Higher concentration of nitrogen was observed in retted coirpith inoculated with the same fungi. The phosphorus content was maximum m non retted coirpith inoculated with P. eous, C. indica-Z; S. commune and P. squarrosulus. Maximum potassium content was observed In non retted coirpith treated with P. eous and P. sajor-caju. P. eous and P. sajor-caju treated retted coirpith brought about maximum reduction in cellulose, while lignin degradation was maximum for P. sajor-caju and P. eous treated non retted coirpith. P. eous brought about the maximum reduction in weight of retted and non retted coirpith, while maximum volume reductioh was noticed in retted and non retted coirpith inoculated with P. eous and S. commune respectively. The final compost was dark brown in colour with low levels of organic carbon, cellulose, lignin, narrow C : N ratio and with increased nutrient status. The results of the experiment clearly showed that P. eous, P. sajor- caju and S. commune are efficient decomposers of coirpith.
Effect of application of plant protection chemicals on the survival of Rhizoctonia solani Kuhn
(Department of Plant Pathology, College of Agriculture, Vellayani, 1986) Lulu Das; Chandrasekharan Nair, M
In Kerala, the incidence of sheath blight of rice is endemic causing great economic loss. The present investigation was undertaken to make a critical assessment of the efficacy of various palnt protection chemicals, viz., fungicides, insecticides and herbicides on the incidence and intensity of sheath blight of rice and on the survival of the pathogen. The organism was isolated from naturally infected rice fields and its pathogenicity proved. Studies on the viability of sclerotia revealed that they sclerotia remained viable upto 210 days in all the different types of soils namely sandy, clayey and loamy. The organism could survive on straw bits upto 180th ady only.
Integrated management of sheath rot of rice (Oryza sativa L.)
(Department of Plant Pathology, College of Agriculture, Vellayani, 1997) Blessy Jose; Lulu Das
Sheath rot disease of rice, caused by Sarocladium oryzae Gams and Hawksworth, is one of the most important diseases of rice in Kerala. The present investigation was to work out an efficient ecofriendly integrated control measure utilising biocontrol agents and plant products in combination with the minimum dose of fungicides against this disease. The antagonists found effective against Sarocladium oryzae are Trichoderma sp., Aspergillus sp. and Penicillium sp. Among these, Trichoderma sp. was found to decrease the disease intensity and increase the yield, the most. tried, best. Among the various methods of application of antagonists seed treatment and root dip method were found to be the In the pot culture trial conducted to find out the mode of action of antagonists under various systems of application, none of the treatments proved superior to others. Leaf extract of Ocimum sanctum (10 per cent) had maximum inhibition of the radial growth of the fungus. Minimum dry weight was seen with the bulb extract (10 per cent) of Allium sativum and extract (10 per cent) of Ocimum sanctum. Carbendazim at 0.025 per cent concentration brought about 100 per cent inhibition of radial growth and mycelial weight of S. oryzae. Total inhibition of radial growth of the fun~u9 WBB achieved by the application of 0.25 per cent Ediphenphos and total inhibition of the mycelial growth was achieved by the application of Ediphenphos at 0.075 per cent concentration. For mass multiplication of antagonists, bits of jack seeds proved to be the best substrate for Trichoderma ap. as evidenced by fungal growth. Tapioca rind and wheat grains was the best suited Aspergillus ap. Wheat bran:sand (1:10 w/w) proved to be the best medium for Penicillium sp. For Pestalotiopsis Sp., wheat bran: sand mixture at a proportion of 1:3 and 1:10 were found equally good. The integrated management practices revealed that none of the treatments were superior over others when yield and disease intensity were considered. However, least disease intensity was noticed with the application of Trichoderma sp. as seed treatment, followed by foliar spray of Ediphenphos and leaf extract (10 per cent) of Ocimum sanctum. Highest yield was obtained in the treatment combination of Trichoderma sp, applied as seed treatment followed by the foliar application of Carbendazim and the bulb extract (10 per cent) of Allium sativum.
Standardization of techniques for cultivation of button mushroom (Agaricus spp.) in Kerala
(Department of Plant Pathology, College of Agriculture, Vellayani, 2015) Lishma, N P; Lulu Das
The work entitled "Standardization of techniques for cultivation of Button mushroom (Agaricus spp.) in Kerala" was conducted during the period 2013 - 2015 at College of Agriculture, Vellayani. The aim of study was to explore the possibility of cultivation of Agaricus species and develop a modified technique for the production of quality compost with alternative agricultural waste. A preliminary survey was conducted for the collection of various isolates of Agaricus spp. during and after south - west monsoon in different locations. The five isolates obtained along with the two isolates available at AICRP centre, Vellayani were sent to DMR and accession numbers were obtained for all the isolates.The isolate 7 identified as Agaricus bisporus (Lange) Imbach which showed maximum growth on potato dextrose agar as well as intensive spawn run on paddy grains was selected for further studies. Studies revealed that maximum vegetative growth was observed on potato dextrose agar and it preferred a temperature of 24 °C with a pH of 6. It was also observed that dark phase favoured the growth of A. bisporus. Among the different carbon and nitrogen sources tested, glucose and beef extract supported maximum growth of A. bisporus. The study on evaluation of different substrates for spawn production revealed that in paddy grains spawn run was completed within twelve days which was the best. Evaluation of various compost and casing material combinations revealed that pearl millet straw, poultry manure, urea and gypsum + coir pith was the best with a total yield after three harvests of 325.97 g per kg bed followed by pearl millet straw, poultry manure, urea and gypsum + tea waste (301.76 g per kg bed). No mycelial growth was observed in all combinations of sawdust, poultry manure, urea and gypsum as well as wheat bran, poultry manure, urea and gypsum with different casing materials. The pest and disease incidence during the cultivation period of A. bisporus was studied and it was observed that sciarid flies and staphylinid beetles were prevalent during sporocarp formation. The competitive fungi recorded were Trichoderma sp. and Coprinus sp. during spawn run, casing and sporocarp formation. The study also showed that mushrooms stored under refrigeration (4 °C) had maximum shelf life of 7 days compared to those stored at room temperature. Sensory evaluation of mushroom recipes were carried out by a panel of judges for attributes like colour, texture, flavor and taste using a five point score card. Among the various products mushroom soup obtained an overall acceptability of 4.7. From this study it can be concluded that growth of A. bisporus was maximum in potato dextrose agar at a temperature of 24 °C with a pH of 6 in dark phase. Glucose and beef extract were found to be the best carbon and nitrogen sources respectively. Compost prepared from pearl millet straw, poultry manure, urea and gypsum overlaid with coir pith compost as casing material supported maximum growth and yield of A. bisporus.
Standardization oftTechnique cultivation of Tricholoma giganteum massee in Kerala
(Department of Plant Pathology, College of Agriculture, Vellayani, 2013) Prathibaha, P R; Lulu Das
Strain evaluation and production technology of shittake mushroom ( Lentinula edodes ( Berk. ) pegler)
(Department of Plant Pathology, College of Agriculture, Vellayani, 2016) Deepa Rani, C V; Lulu Das
The present investigation on "Strain evaluation and production technology of Shiitake mushroom (Lentinula edodes (Berk.) Pegler' was conducted at Department of Plant Pathology, College of Agriculture, Vellayani, Thiruvananthapuram during the period 2012-2015. The aim of the experiment was to exploit various strains of Lentinula spp. for novel production technology and their phylogeny analysis through physiological and molecular studies. Surveys were collected during pre and post monsoon periods of May to December from different parts of Thiruvananthapuram, Kollam, Wayanad, Idukki, Pathanamthitta, Kannur and Kasargode districts. Six isolates of sp. (VLYN- 1 to VLYN-13) obtained during the survey were identified and compared with procured reference strains of Lentinula edodes (LE-1 to LE-5 from GB Pant University of Agricultural and Technology, Pantnagar, Uttarakhand) and LE-6 strain (Maharana Pratap University of Agriculture and Technology, Udaipur) . Morphologically the native isolates of Lentinus spp. had concave, funnel and convex pileus with varying colors and were leathery in nature.L. edodes strains in contrast had convex pileus with chocolate brown and golden yellow sporocarps which were fleshy and edible. Phylogenetic analysis of all six strains of L. edodes using RAPD markers confirmed the variability between the strains. Maximum similarity coefficient of 74.10 per cent was observed between LE-2 and LE-6 strains while LE-2 and LE-4 strains showed a minimum similarity coefficient of 35.70 per cent. Further studies by ITS sequencing showed that all the L. edodes strains tested in the study showed 99- 100 per cent similarity with the known sequences off L. edodes available in NCBI database while that of native isolates showed 99- 100 per cent similarity to Lentinus tuber-regium and Lentinus connatus thus confirming the variability between Lentinus and Lentinula sp. All the six strains of L. edodes, showed maximum mycelial growth in malt extract peptone dextrose agar in solid and oat meal broth in liquid medium. L. edodes strains preferred temperature of 20 °C with an acidic pH of 6. Dark and ambient light conditions favored maximum mycelial growth and biomass production for L. edodes culture. Although a minimum period of 16.33 days was required for full mycelial run in maize grains but due to comparatively less contamination rate in paddy grains which took 18.33 days for completion of mycelial run were selected as best substrate for further studies. Different substrates were evaluated for the development of a cultivation package for shiitake mushroom. Results showed that LE-1 strain took minimum of 71.00 days for initiation of sporocarp in sawdust supplemented with 20 per cent wheat bran. Hard wood sawdust especially of teakwood was used in the study. The substrate based on paddy straw and banana pseudo stem were not found effective for pinhead initiation and thus failed to produce sporocarps. LE-1 produced maximum sporocarp (11.33) in sawdust + 20 per cent wheat bran which was followed by LE-3 (10.63) in sawdust + 20 per cent rice bran. Maximum yield of 290.66 g/ 500 g substrate was obtained in sawdust + 20 per cent wheat bran by LE-6 strain. Maximum biological efficiency of 58.13 per cent was also recorded in LE-6 in sawdust supplemented with 20 per cent wheat bran substrate. Substrates like paddy straw and sawdust amended with 20 per cent wheat bran substrates were evaluated for the development of native isolates of Lentinus tuberregium and Lentinus connatus . Results showed that maximum biological efficiency of 58.00 per cent was obtained by Lentinus tuber-regium whereas 36.60per cent biological efficiency by Lentinus connatus in sawdust amended with 20 per cent wheat bran substrate. Nutrient analysis of all the six strains showed that carbohydrate content ranged between 35.29 per cent to 40.23 per cent, protein 18.33 per cent to 21.66 per cent, crude fibre 22.33 per cent to 27.33 per cent, Vitamin- C 2.53 per cent to 3.50 per cent, ash 2.70 per cent to 4.40 per cent and lipid 2.46 per cent to 3.60 per cent. Mineral content of L. edodes included Ca (11.00 mg to 19.00 mg/ 100 g), Mg (0.46 to 1.10 mg/ 100 g), Fe (1.36 mg to 1.80 mg/ 100 g), Mn (1.53 mg to 2.63 mg), P (1.65 mg to 2.87 mg), K (16.33 mg to 25.20 mg), Na (13.00 mg to 23.66 mg) and Zn (19.66 mg to 28.33 mg/ 100 g). Sensory evaluation of mushroom products made from L. edodes was carried out by a panel of judges for various characters of which mushroom masala scored maximum for texture, taste, flavor and overall acceptability when compared to other recipes like mushroom cutlet, scramble, soup, baji and biscuit. As part of the study, paddy grain was found to be the most suitable substrate for spawn production of L. edodes and teakwood sawdust amended with 20 per cent wheat bran was the most efficient bed substrate. LE-6 strain was superior in terms of yield and biological efficiency. Therefore findings of the above investigation recommends the adoption of a suitable cultivation package for shiitake mushroom by using low cost substrates (hardwood sawdust) available in Kerala in plains and hilly regions.